ejabberd: 20.12 -> 21.04

[Izorkin]

Motivation for this change

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS linux)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Determined the impact on package closure size (by running nix path-info -S before and after)
• Ensured that relevant documentation is up to date
• Fits CONTRIBUTING.md.

[r-rmcgibbo]

Result of nixpkgs-review pr 122569 at f04448c run on x86_64-linux 1

1 package built successfully:

• ejabberd

1 suggestion:

• warning: unclear-gpl

  gpl2 is a deprecated license, please check if project uses gpl2Plus or gpl2Only and change meta.license accordingly.

  Near pkgs/servers/xmpp/ejabberd/default.nix:115:5:

      |
  115 |     license = licenses.gpl2;
      |     ^
  

---

Result of nixpkgs-review pr 122569 at f04448c run on aarch64-linux 1

1 package built successfully:

• ejabberd

[hrhino]

It appears that the license for this should be gpl2Plus according to the files' license headers; oddly, though, there are a few (such as src/mod_mqtt_ws.erl) that claim to be apache v2...

[hrhino]

[nix-shell:~/.cache/nixpkgs-review/pr-122569]$ results/ejabberd/bin/iex
/nix/store/a94napnlmxxvlsvycqf0ynnd6w0igrbq-ejabberd-21.04/bin/elixir: line 126: exec: erl: not found

I'm getting this if I try to run iex or mix binaries... presumably those scripts should have their ERL_EXEC="erl" lines patched.

[hrhino]

see above comments